The present invention relates to a hose connector adapted to have a flexible polymeric hose fitted on the outer periphery of the hose connector. More specifically, it relates to a hose connector comprising a sealing element mounted on the end of a metal tubing.
A hose connector formed at the end of a metal tubing is typically used to connect the metal tubing to a flexible polymeric hose. The metal tubing can be part of a long rigid fluid line or a stem defined at the end of a metal connector body. The polymeric hose is fitted on the outer periphery of the hose connector to form a fluid connection between the fluid line or connector body with the polymeric hose. A typical prior art hose connector adapted to have a flexible polymeric hose fitted on the outer periphery of the hose connector is illustrated in FIG. 1. The hose connector 10 has a pair of beads 20, 26 extending radially outward from the remainder of a metal tubing 14. Each bead 20, 26 has a lead-in portion 22, 28 and a slip-out preventive portion 24, 30. The lead-in portions 22, 28 allow the hose 18 to slide axially inward along the outer surface of the metal tubing 14. The slip-out preventive portions 24, 30 enhance the retention of the hose 18 onto the metal tube 14. For this type of hose connector, a fluid tight seal is maintained only by the tightness of the hose 18. Therefore, when creep deformation of the hose occurs due to heat deterioration, the holding force decreases such that a fluid tight seal cannot be maintained. Other factors which contribute to a lack of fluid tight seal include variations in the size and tolerances of the hose connector and the polymeric hose, the inner surface finish of the hose, the outer surface finish of the metal tubing, and the hardness of the hose.
To maintain a fluid tight seal for a long period of time, a resilient O-ring can be installed on the outer surface of the metal tubing such that once the flexible polymeric hose has been positioned over the O-ring, the O-ring will be radially deformed between the hose and the metal tubing to provide a fluid tight seal. Two types of hose connectors having a resilient O-ring installed and retained onto a metal tubing are known and disclosed in prior art references. One such type of hose connectors is illustrated in FIG. 2. The hose connector 10 has an annular channel 132 formed around the outer surface of the metal tubing 114. An O-ring 136 is situated in the annular channel 132. An example of such a hose connector with an annular channel formed around the outer surface of the metal tubing is disclosed in U.S. Pat. No. 5,135,268.
Another type of hose connectors having an O-ring installed and retained onto a metal tubing is illustrated in FIG. 3. The hose connector 210 uses a separate end form 234. The end form 234 is mounted to the end of the metal tubing 214 having an upset 220 formed thereon. The end form 234, along with the upset 220 of the metal tubing 214, forms a channel 232 for an O-ring 236 to be situated therein. An example of such a hose connector with an end form mounted to the end of a metal tubing is disclosed in the U.S. Pat. No. 5,779,286.
While for certain applications, an O-ring installed and retained onto a metal tubing is an improvement over the prior art hose connector illustrated in FIG. 1, it does have several disadvantages. One disadvantage is that during the insertion of the hose connector into the hose, the O-ring may roll out of the channel and is then unable to provide an adequate fluid seal. Another problem associated with using an end form, as illustrated in FIG. 3, is that a component, separate from the sealing element, must be mounted to the end of the metal tubing. This usage of the an end form increases the cost of the hose connector by requiring the manufacturing of a separate end form and the steps of installing the O-ring to the end form and inserting the end form into the metal tubing.